790  AutoCAD  and  Its  Applications—Basics  Copyright  Goodheart-Willcox  Co.,  Inc.  Assigning  a  Stretch  Action  Figure  26-10  illustrates  the  process  of  adding  a  stretch  action  to  the  bolt  symbol  example.  Access  the  Stretch  action  option  and  pick  the  Shaft  Length  parameter.  Then  specify  a  parameter  point  to  associate  with  the  action.  Move  the  crosshairs  near  the  appropriate  parameter  point  to  display  the  red  snap  marker,  and  pick  to  select.  Alternatives  include  selecting  the  sTart  point  option  to  pick  the  start  point  of  the  linear  parameter  or  the  Second  point  option  to  select  the  endpoint.  If  you  plan  to  use  grip  editing  to  control  the  block,  and  added  a  single  grip,  specify  the  point  with  the  grip.  Next,  create  a  window  to  defi  ne  the  stretch  frame.  This  is  the  same  technique  you  apply  when  using  the  STRETCH  command.  See  Figure  26-10A.  Then  pick  the  objects  to  stretch,  including  the  associated  parameter.  You  do  not  need  to  use  a  crossing  window,  because  the  previous  operation  defi  nes  the  stretch.  However,  crossing  selection  is  often  quicker.  See  Figure  26-10B.  Press  [Enter]  to  place  the  action  icon.  Test  and  save  the  block,  and  exit  the  Block  Editor.  The  dynamic  block  is  now  ready  to  use.  Using  a  Stretch  Action  Dynamically  Figure  26-11  shows  the  bolt  block  reference  selected  for  editing.  The  linear  param-  eter  grip  is  a  light  blue  arrow  at  the  far  end  of  the  bolt  shaft.  The  insertion  base  point  specifi  ed  when  the  block  was  created  appears  as  a  standard  unselected  grip.  Select  the  parameter  grip  and  stretch  the  shaft  to  the  new  length.  Use  dynamic  input  to  view  the  stretch  dimension,  and  enter  an  exact  length  value  in  the  distance  fi  eld.  You  can  also  use  the  Properties  palette  to  defi  ne  the  distance.  PROFESSIONAL  TIP  P  R  OFESSIONAL  TIP  The  dynamic  input  distance  fi  eld  is  a  property  of  the  linear  parameter,  allowing  you  to  enter  an  exact  distance.  To  get  the  best  results  when  using  a  linear  parameter,  it  is  important  that  you  locate  the  fi  rst  and  second  points  correctly.  Ribbon  Block  Editor  Action  Parameters  Stretch  Type  BACTIONTOOL  Stretch  stretch  action:  An  action  used  to  change  the  size  and  shape  of  block  objects  with  a  stretch  operation.  Figure  26-10.  Assigning  a  stretch  action  to  a  linear  parameter.  A—Specify  the  parameter  and  parameter  grip,  and  create  a  window  for  the  stretch  frame.  B—Select  the  objects  to  be  included  in  the  stretch  action.  2.  Pick  near  the  parameter  point  4.  Pick  the  second  point  for  the  stretch  frame  5.  Pick  the  first  point  of  the  crossing  window  6.  Pick  the  second  point  of  the  crossing  window  3.  Pick  the  first  point  for  the  stretch  frame  1.  Pick  the  linear  parameter  A  B